This application incorporates by reference Taiwanese application serial No. 88119802, filed Oct. 11th, 1999.
1. Field of the Invention
The invention relates in general to the method for analyzing a sample waveform in the time domain, and more particularly to the method for analyzing a sample waveform and comparing of the sample waveform and its original input in the time domain in an efficient way.
2. Description of the Related Art
Computer systems nowadays are capable of processing audio and video data. For dealing with audio and video, computer systems are equipped with hardware and software for processing audio and video data. For instance, a coder/decoder (CODEC) is utilized in the circuitry for processing signals from audio channels, such as the LINE-IN or CD-IN channels, of an audio add-in card or a main board with built-in audio chips of a computer system. For the software instances, audio recording/playing applications and video recording/playing applications are the applications bundled with the computer peripherals or computer systems. Thus, for the testing of these hardware and software products, a method of analyzing the sample waveform is required by comparing the sample waveform with the original waveform for the purpose of determining whether the functionality of the circuitry or the application is working properly. In addition, if the software application works properly, the testing is further able to test whether the hardware product is working properly.
Generally, the fast Fourier transform (FFT), which converts the sample waveform from a time domain to a frequency domain, is the conventional method used. Further analysis is then performed in the frequency domain. However, it has the drawbacks that it requires many complicated and time-consuming calculations.
It is therefore the object of the invention to provide a method of analyzing a sample waveform in the time domain. According to the invention, the analyzing and comparing of the sample waveform and its original are quickly completed in the time domain without using the FFT. In addition, by using the method in the testing of a waveform processing module, such as a circuitry for processing signals from audio and/or video channel, the test result is obtained easily and quickly.
In accordance with the object of the invention, it provides a method of analyzing a sample waveform in the time domain which includes the following steps. Firstly, a periodic wave is inputted into a waveform processing module for obtaining the sample waveform. Next, a determination is made as to whether the sample waveform is recognizable. If not recognizable, the amplitude of the periodic wave is increased and the previous steps are repeated until the sample waveform is recognizable. If recognizable, the period of the sample waveform is determined. For the determination of the period, a number of peaks of the sample waveform are detected. After that, a determination is made as to whether the period of the sample waveform is obtainable from all of the peaks obtained above. If not obtainable, the method discontinues and it indicates the waveform processing module is malfunctioning. If obtainable, the period is determined and a determination is then made as to whether the period of the sample waveform is equal to a predicted period of the sample waveform. If equal, it indicates the waveform processing module is functioning. If not equal, it indicates the waveform processing module is malfunctioning.